Efficient look-ahead load margin and voltage profiles contingency analysis using a tangent vector index method

Abstract

Given the current operating condition at each bus from real-time database, from the short-term load forecast, or from near-term generation dispatch, we present a method for real-time contingency prediction and selection in current energy management systems. This method can be applied to contingency prediction and selection for the near-term power system in terms of load margins to collapse and of the bus voltage magnitudes. The propose algorithm uses only two tangent vectors of power flow solutions and curve fitting based techniques to perform look-ahead load margin and voltage magnitude simultaneously. Therefore, it can overcome the traditional snap-shot contingency analysis methods. Simulations are performed on IEEE 57 and 118-bus test systems to demonstrate the feasibility of this method.

1 . An efficient look-ahead load margin and voltage profiles contingency analysis that uses a tangent vector index method comprising the steps of: 
 calculating a current between two points after contingency; and    estimating a voltage of a collapse point by using curve of the second degree and tangent vector.    
   
   
       2 . The method as claimed in  claim 1 , wherein to estimate the voltage of the collapse point comprises the steps of: 
 using the value from continuation current to estimate the collapse point after contingency; and    calculating a new tangent vector in a new work point and repeating the steps till the error within a purposed range.